1. Field
Embodiments discussed herein relate to an image processing apparatus and an image processing method.
2. Description of the Related Art
In the related art, MPEG-4 (Moving Picture Experts Group phase 4) AVC (Advanced Video Coding)/H.264 exists as an international standard for video coding. In MPEG-4 AVC/H.264, an encoder computes predictive error between an input picture and a predictive picture, conducts orthogonal transformation, quantization, reverse quantization, and inverse orthogonal transformation, and reconstructs the predictive error. The encoder generates a decoded picture based on the reconstructed predictive error and a predictive picture within the frame (i.e., an intra-predictive picture) or a picture predicted among frames (i.e., an inter-predictive picture). The encoder generates inter-predictive pictures based on a decoded picture and an input picture. The encoder outputs a bit stream encoding quantization coefficients. The decoder decodes the bit stream, and reconstructs the predictive error by conducting reverse quantization and inverse orthogonal transformation. The decoder generates a decoded picture based on the predictive picture obtained by the reconstructed predictive error and the decoding of the bit stream.
Meanwhile, intra encoding process using intra-prediction is performed in macroblock units having 16 pixels horizontally by 16 pixels vertically, or in block units obtained by sub-dividing each macroblock into blocks having 4 pixels horizontally by 4 pixels vertically or 8 pixels horizontally by 8 pixels vertically. For chroma, an encoding process using intra-prediction is performed in block units obtained by sub-dividing each macroblock into blocks having 8 pixels horizontally by 8 pixels vertically. When the encoding process proceeds from the upper left to the lower right of a single source frame, the blocks (or macroblocks) above, diagonally left and above, diagonally right and above, and immediately left of the block or macroblock to be encoded (hereinafter collectively referred to as the encoding target block) have already been encoded.
Predictive pictures for the luma of 4×4 blocks or 8×8 blocks (pixels horizontally by pixels vertically) are generated based on the pixels lining the bottom edges of the blocks above and diagonally right and above the encoding target block, the pixel at the lower-right corner of the block diagonally left and above the encoding target block, and the pixels lining the right edge of the block immediately left of the encoding target block. In addition, predictive pictures for chroma blocks are generated based on the pixels lining the bottom edge of the macroblock or block immediately above the encoding target block, the pixel at the lower-right corner of the macroblock or block diagonally left and above the encoding target block, and the pixels lining the right edge of the macroblock or block immediately left of the encoding target block.
Technology like the above is disclosed in Japanese Laid-open Patent Publication No. 2009-21786 and Japanese Laid-open Patent Publication No. 2008-227670.